• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

engine troubles....

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
P

pugs2300

RCTalk Talkaholic
Messages
309
Reaction score
0
Points
0
RC Driving Style
  1. Bashing
ok guys...I'm having some troubles with my 3.3 on my Tmaxx....
when i first start it up it runs great...probably for the first 5 minutes or something it has great power and response...it will flip on command...
but after a few minutes, like after it gets good and warm, it will just quit...
it will start back...but it will quit again as soon as you try to take off and play...
put it up and get it out the next day.....
same exact thing...starts off strong as hell then kuput...it wont stay running at all...
i tried to retune it...went back to stock settings and started over with the same end results...its puttin out a nice solid smoke...not to much but enough
it doesn't act lean or rich...it sounds like it should when its running...

like always any insight is appreciated...thanks..

i swear if it wasn't for this forum and all the awesome people on it willing to help out i would have a gigantic box of rc's broke in half out of frustration...lmao...not really the hobby for the impatient is it...
 
what temp are you running at ??...maybe your running to hot ...keep in mind , depending on where you live , stock settings may be to lean .....i have 2 3.3 and they both run at least 5 turns out on the HSN during normal weather ( both engines are sealed ) ....and stock setting is 4 turns out
 
play with your idle screw alittle bitturn it clockwise 1/16 at a time and do a high speed run stop it infront of you and do again if it still wont idle.......
 
ok here are the symptoms of this damn motor as of right now...
oh last night i tore it down cleaned everything and sealed the motor...
also i cleaned the carb because i noticed some gummed up fuel in the slide area...i took both needles out and cleaned the entire carb and blowed all the crap out of it...
today i tried to run it...it had a hard time even starting at first but i noticed it didn't seem to be gettin fuel so i primed the lines by blowin through the exhaust pressure line...it fired as soon as it cranked...but quit immediately...
after playin with it for a minute i got it where it would start and take off at WOT but as soon as i let off it would die again...also i could start it and keep the idle just a bit high and just barley creep around the yard but it would die after 10-15 seconds...it seemed it would run WOT as long as i had road for but would die as soon as i let of the throttle...
i have had the motor apart twice and i see no damage...the carb was pretty gummy but i cleaned it well...needles are set stock when i start and no matter what i try it just won't run...just looking for more ideas
i have adjusted everything i can every way i can think to adjust it...I'm goin to go cry in a corner now...excuse me...:(
 
have you tried a fresh plug? inspected your fuel lines for cracks or plugged?
fresh and clean air filter?
 
To me it sounds like the engine might be shot, meaning that it no longer has enough compression to run. When my 2.5 went out, it would run great until it was warm, then it wouldn't stay running for anything. I don't know how it might have acted after tearing it down and cleaning it all up, because I realized that it was done before I tried that. So my suggestion is to check and see if it has compression, if the flywheel turns very easily, then there is too little compression.
 
yea i tried changing the plug...i looked at the fuel lines...they seem fine...the air filter could surely need cleaning but isn't at all dirty beyond the point of makeing the engine run...and as far as the engine being shot...i don't believe it is...it has lots of compression....a noticable amount more than my revo...which runs fine....the engine has less than a gal or so of fuel through it and it hasn't been abused...I'm just at a loss for ideas...i am gonna try putting the carb off my revo on it just to be sure there isnt a prob there....
 
Did you check the conrod and bearings when you had it apart? It's not uncommon for a 3.3 to chew bearings or split a rod in one gallon of use. What type of plug are you using? Have you tried a good hot plug?
 
what and how old is the fuel you are using?
i thought i has lost an engine only to find out i had bad fuel.
fuel had started to evaporated leaving me with more oil content, had good smoke trail but was running lean because i miss read the smoke trail.
got new temp gun and fuel , now its a screamer

just a thought on something else to check
 
wildjokerracing said:
what and how old is the fuel you are using?
i thought i has lost an engine only to find out i had bad fuel.
fuel had started to evaporated leaving me with more oil content, had good smoke trail but was running lean because i miss read the smoke trail.
got new temp gun and fuel , now its a screamer

just a thought on something else to check
Click to expand...

well its a thought...the fuel i am using is from last summer but i never opened it until about 2 or 3 weeks ago so i assume its good to go...hell i try some new fuel as soon as i get some...lol...there isn't a LHS anywhere Local...
 
If the engine's still good, then it sounds like it's probably running much too lean. The factory settings my be too lean for your location, which could make it hard to tune from factory. If it's running lean, it would run really well before it heats up, and then quickly overheat and expand to a point where it doesn't have the compression to run correctly. Try to get it running really rich, and then lean it out from there and see if that fixes it.
 
The same thing happens to me with my force 32 big block. My problem was that my idle was set to low or had vibrated a little. try leaning out your idle a little bit to see if it improves.
 
turn the lsn counterclockwise and mess with the idle as well. It might take a few tanks to get it just right..... And if you still can't get it then there might be an airleak somewhere........ goodluck and hope you can figure it out
 
I am no expert when it comes to nitro engines but I am hooked. I run my t maxx almost every weekend. I have had mine for about 4 months and roughly 4 gallons of fuel. I had the same problem with my truck this weekend. It would start and run at wot but died if I let off of the throttle. It ended up being the spring around the clutch shoes. It was broken on one end. I made a new loop and reconnected. Problem solved. I hope this helps.
 
ok guys i took the engine back apart yesterday and i think i may have found the problem....i took the cooling head off and the plate off the side to look at the rod and stuff again...and i noticed when i spin the flywheel when the piston gets to TDC it feels like there is a bad place in one of those bearings...it almost feels like it has compression with the head off of it...so i took out the sleeve and piston and rod....the sleeve was a lot tighter than the one on my revo was...i had a hard time getting it out...and back in for that matter...anyhow when i spun the flywheel without the rod and stuff attached to it everything felt very smooth with no noticeable rough spots while spinning it...i took out the flywheel and that shaft to have a better look at the bearings and they both look ok....so i put it all back together minus the head and it still feels tight at TDC....it gets to a tight spot then it loosens up right when the pistons tops out and it gets tighter again right when it starts goin back down...


question is...do you all thing its the bearings even though they feel perfect when you don't have the rod attached....or would it maybe be the piston and sleeve....both of them look good to...no noticeable wear or anything...
thanks for the help guys...you all are whats keepin at this....and i appreciate it...
 
Sounds like a loss of compression to me you may have a warped head.Don't take it personal but usally people are better at destroying engines than fixing them.(Part of the learning prosses.:p:PS. the 3.3 is a piece of crap buy an os.21!
 
Last edited:
I dont say they are crap everything has its problems.. I have had alot of luck and fun with the 3.3.
 
pugs2300 said:
ok guys i took the engine back apart yesterday and i think i may have found the problem....i took the cooling head off and the plate off the side to look at the rod and stuff again...and i noticed when i spin the flywheel when the piston gets to TDC it feels like there is a bad place in one of those bearings...it almost feels like it has compression with the head off of it...so i took out the sleeve and piston and rod....the sleeve was a lot tighter than the one on my revo was...i had a hard time getting it out...and back in for that matter...anyhow when i spun the flywheel without the rod and stuff attached to it everything felt very smooth with no noticeable rough spots while spinning it...i took out the flywheel and that shaft to have a better look at the bearings and they both look ok....so i put it all back together minus the head and it still feels tight at TDC....it gets to a tight spot then it loosens up right when the pistons tops out and it gets tighter again right when it starts goin back down...


question is...do you all thing its the bearings even though they feel perfect when you don't have the rod attached....or would it maybe be the piston and sleeve....both of them look good to...no noticeable wear or anything...
thanks for the help guys...you all are whats keepin at this....and i appreciate it...
Click to expand...

Its designed to be a little snung at the top thats the pinch if its to tight you may have distorted the sleeve from over heating if you did.Slide the piston in by hand to see if there is any hard spots except at the top you could have a bad rod causing a bind.
 

RC Builds

Back
Top